A set of Advisors that are designed to enforce MySQL best
practices for that specific category. For example, there are
predefined advisor categories such as
Administration,
Availability, Cluster,
Replication and Security.

A component that the MySQL Enterprise Monitor product monitors,
such as a MySQL server
instance, or a CPU or file
system within a server machine. Contrast with
metric, which is a property
within the component that is measured.

The Groups shown in the Asset
Selector are the ones you create and manage (on the
MySQL Instances Dashboard, or during Agent
installation) and those that are discovered automatically from
monitoring replication topologies. It is on the left side of
many UI pages that controls content in the main-body of the
page.

B

backlog

The agent backlog is a caching mechanism which stores monitoring
data in the event the agent cannot communicate with the MySQL
Enterprise Service Manager. The backlog can store 10MB of
monitored data in active RAM.

A function of Event Notification, it is a time period where
events do not trigger notifications via the Event Handler, in
that information is not reported from a MySQL Server. Typically,
this is during a maintenance period when the database might go
through an unusual workload that does not require raising any
notifications.

An aspect or component of a system whose capacity imposes a
limit on performance. In MySQL Enterprise Monitor, you identify
bottlenecks in areas such as I/O or memory usage using
graphs, and use
advisors to automatically raise
events when problems occur.

The MySQL Enterprise Monitor product interfaces with many
different databases and other kinds of servers. Each of these
components can have its own login and security credentials.
MySQL Enterprise Monitor pulls performance data from the MySQL
servers that you monitor, stores the resulting data in a
repository that is also a MySQL
server, and sends alerts by communicating through other kinds of
servers such as SMTP for e-mail
alerts and NMS for
SNMP traps. It pulls
support-related data from the My Oracle
Support site. You view the results in the
UI, which is protected by its
own login and optionally by
LDAP authentication.

D

data collection item

Data values derived from server status variables, operating
system status information, and MySQL table information. You can
reference these items using mnemonic names in
expressions when you create or
edit rules.

Events are displayed if an Advisor Threshold is crossed, and are
used to inform you of errors or potential problems with your
implementation. Monitor events using the
Events page, and define how
events are handled by configuring Event
Handling.

A textual report showing the internal mechanisms used by a
query, and estimates for the
“cost”, such as amount of data to process, involved
in each step. Performance monitoring involves checking whether
queries that are slow or frequently run could be sped up or made
less resource-intensive, by examining the EXPLAIN plan to check
if the MySQL optimizer has chosen the most efficient ways to
process indexes, order join clauses, and so on. The MySQL
Enterprise Monitor product includes a number of features for
visualizing EXPLAIN plans. These features are
language-dependent, relying on support in the various
Connectors for programming
languages and frameworks.

F

An aspect of a SELECTquery that often indicates a
performance or scalability issue. The query scans every row in a
table, rather than using an index to look up a subset of rows.
It can be a non-issue for small tables that are cached in
memory. It can be unavoidable when querying large tables to
prepare reports. Performance issues are most likely when the
table being scanned is involved in a join operation, when the
query is run frequently, or when the result set only references
a small fraction of the rows in the table.

To diagnose possible issues due to full table scans, choose a
time period of heavy SQL activity from one of the
graphs, use the
Query Analyzer to locate
queries that process large numbers of rows, and examine the
explain plan for the queries.
The notation in the explain plan that indicates a full table
scan is Type=ALL.

G

H

heartbeat

An implementation detail from MySQL Enterprise Monitor 2.x that is no longer
present. A heartbeat signal that is sent from an Agent to the
Service Manager was defined as the heartbeat, and was present in
the connecting URL.

A persisted instance of a
run-time metric evaluation.
These may store the raw metric data, or the result of an
expression or function against a metric. Instruments are
generally stored for things that will show in the GUI, such as
graph data.

Core information about a host or MySQL server
instance. This data is
collected by the Agent. The
inventory includes details such as the MySQL server version
number, supported storage engines and
replication configuration. The
data in the inventory helps to determine what other kinds of
data can be collected from the hosts and MySQL servers.

J

Java

The MySQL Enterprise Plugin for
Connector/J enables any application using the Connector/J JDBC
driver to supply query analyzer
information directly to MySQL Enterprise Service Manager.
Information is sent to the MySQL Enterprise Service Manager for
analysis without any need to modify your applications.

The MySQL Enterprise Monitor product is partly built on Java
technology, using the Tomcat
servlet container for the web-based GUI. It uses a JRE on the
machine that runs the Service
Manager, its performance is affected by the Tomcat
configuration parameters, the Agent is written in Java, and
during troubleshooting you might use diagnostic information from
the Java environment.

Oracle JavaScript Extension Toolkit (JET) is a collection of
open source JavaScript libraries along with a set of Oracle
contributed JavaScript libraries used to build applications that
consume and interact with Oracle products and services.

L

LDAP

An authentication mechanism that can control access to the
UI. On Linux, Unix, and OS X
systems, you might have a separate LDAP server where each user
has their own credentials. On
Windows systems, the LDAP protocol is used to connect to an
Active Directory server for the same authentication purposes.
Typically, you map LDAP roles to corresponding MySQL Enterprise
Monitor roles, to enable groups
of users to have basic or administrative access to the Dashboard
without configuring each user individually, or giving them a new
user ID and password, or requiring extra work to revoke access
when they leave the organization.

A programming language that is used for parts of the Service
Manager. Although you do not need to know this language to
operate MySQL Enterprise Monitor, you may need to specify options containing
file paths related to Lua scripts or libraries.

M

master

In a replication configuration,
a database server that sends updates to a set of
slave servers. It typically
dedicates most of its resources to write operations, leaving
user queries to the slaves. In complex
topologies, a server can be
both a master and a slave, known as a
master/slave.

In replication, a server that
acts as a slave to receive
updates from another server, and also acts as a
master to propagate changes to
another set of slave servers. Keeps the top-level master from
having to service too many slaves, and allows certain kinds of
changes to be propagated to a subset of slaves. This
topology is represented as a
tree, with all the intermediate
nodes being master/slave servers.

Any property that is measured using a numeric value. Within
MySQL Enterprise Monitor, such measurements can be displayed
over time as a graph, or an
alert can be sent when a
threshold value is reached.
Each metric is collected from an
asset. For example, how much
time is taken by a database query, or how full is the file
system on a server machine.

To view information about the state, health, activity, and
history of a resource such as a MySQL server
instance. Monitoring can help
to diagnose problems, spot worrisome trends before they turn
into problems, reassure when systems are operating normally, and
notify when an operator needs to take corrective action. With
MySQL Enterprise Monitor, the component you interact with during
monitoring is the UI.

The website for filing bugs and service
requests with Oracle Support. (Commercial customers
such as MySQL Enterprise Monitor users now use the official
Oracle support channel rather than the MySQL bug database.) In
MySQL Enterprise Monitor, you interact with the support site
through the What's New tab.

N

.NET

A programming framework used by many Windows applications,
including the Connector/NET component.

NMS

Acronym for Network Management System, a type of monitoring
system that is separate from the MySQL Enterprise Monitor
product. If your network has this kind of monitoring capability,
MySQL Enterprise Monitor can notify the NMS of network issues by
translating events into
SNMP traps.

A condensed form of the query text used to treat similar queries
as if they were identical, for monitoring performance. When
MySQL Enterprise Monitor normalizes queries, it disregards
differences in keyword capitalization, whitespace, and most
comments. It replaces literal values with placeholders and
transforms multi-row insert statements and IN
clauses, to group similar statements with different parameters
when measuring how much time is consumed by a particular type of
query.

P

PHP

A scripting language typically embedded within web pages.

Q

QRTi

QRTi stands for "Query Response Time index". It is a "quality of
service" measurement for each query, and it uses the Apdex
formula for that calculation. For more information about Apdex,
see: Apdex on
Wikipedia.

In the MySQL Enterprise Monitor context, any SQL statement whose
performance might be monitored. Includes not just SQL
SELECT queries, but also DML statements such
as INSERT, UPDATE, and
DELETE, and DDL statements such as
CREATE TABLE and TRUNCATE
TABLE.

The MySQL Enterprise Monitor component that tracks data about
MySQL queries and summarizes
that data using graphs and
tables. You interact with it (for example, filtering the
displayed queries or selecting a specific time period) using the
Query Analyzer tab in the
UI.

In a replication configuration,
a database server that receives updates from a
source server. Typically used
to service user queries, to minimize the query load on the
master. In complex topologies,
a server can be both a source and a replica, known as a
source/replica.

A set of database features that mirrors the same data across a
set of servers. Used for reliability in case of server failure,
and to speed up queries by dividing the work across servers.
Because replication involves so many aspects of reliability and
performance, it is an important aspect to monitor and has a
dedicated Replication view in
the UI.

The database that stores the monitoring data collected by the
MySQL Enterprise Monitor product. It can be a separate database
instance that is part of the
MySQL Enterprise Monitor installation (the
bundled MySQL server), or you
can use an existing database of your own. The bundled MySQL
server is a level of MySQL database that is fully tested with
the MySQL Enterprise Monitor product, and can be kept separate
from your other databases to avoid any extra load on them. You
might use an existing server that has spare capacity, fast
storage devices, tuned configuration parameters, a backup
system, or other conveniences that can benefit the MySQL
Enterprise Monitor data storage as well.

A level of access privilege for the
UI. One of
manager (highest privilege),
dba, read-only, or
agent (specialized privilege for sending
data). Each user account registered with the Dashboard must have
one of these roles. Components such as the
Agent and the
Aggregator use the
agent role. To simplify the process of
granting credentials for large
numbers of users, you can map
LDAP roles to these MySQL
Enterprise Monitor roles.

S

The core MySQL Enterprise Monitor component that receives the monitoring data
from the Agent,
Aggregator, and
Query Analyzer components. It
displays this information through the GUI web-interface, and
manages the Advisors,
Events, and
Event Handlers, as well as
access to Reporting, Graphing, and Query Analysis.

In a replication configuration,
a database server that receives updates from a
master server. Typically used
to service user queries, to minimize the query load on the
master. In complex topologies,
a server can be both a master and a slave, known as a
master/slave.

A MySQL Server facility for tracking queries
that consume considerable time and resources. MySQL Enterprise
Monitor provides more information about query performance than
the slow query log, and does not currently use the slow query
log itself.

The e-mail protocol for sending
alerts as e-mail messages. To
send alerts this way, you configure e-mail settings similar to
those in an e-mail client.

SNMP

A protocol for sending event
notifications (“SNMP
traps”) to an NMS. The
MySQL Enterprise Monitor product can turn notifications for
selected rules into SNMP traps. In contrast to typical
alerts that are only raised
when some issue occurs, SNMP traps are broadcast for all state
changes, so that corrective action can be cancelled when an
issue is cleared.

In a replication configuration,
a database server that sends updates to a set of
replica servers. It typically
dedicates most of its resources to write operations, leaving
user queries to the replicas. In complex
topologies, a server can be
both a source and a replica, known as a
source/replica.

In replication, a server that
acts as a replica to receive
updates from another server, and also acts as a
source to propagate changes to
another set of replica servers. Keeps the top-level source from
having to service too many replicas, and allows certain kinds of
changes to be propagated to a subset of replicas. This
topology is represented as a
tree, with all the intermediate
nodes being source/replica servers.

For MySQL Enterprise Monitor, the default port used for SSL
connections is 18443. If you are connecting using SSL, the
built-in MySQL Enterprise Monitor certificate is self-signed and
may be highlighted as “unsafe” within the browser
on initial connection. To prevent problems accessing the site,
add an exception for the certificate to your browser for this
server.

standard

The predefined advisors and
graphs supplied as part of
MySQL Enterprise Monitor. Contrast with custom.

The Status Summary widget is displayed on top
of every page, updates dynamically, and shows current status
counters for Hosts monitored, MySQL Instances monitored, MySQL
Instances with invalid connection configurations, Unmonitored
MySQL Instances, and Emergency Events. The counters are live
links for displaying details or resolving the issues they are
reporting.

support issue

Former term for bugs and service requests. In the My Oracle
Support system, now known as a service
request, which is the preferred term.

T

Thresholds are the predefined limits for
Advisors. If the monitored
value breaches the defined threshold, an event is generated and
displayed on the Events page
for the asset. Advisor thresholds use a variety of different
value types, depending on the monitored value. Some use
percentages, such as percentage of maximum number of
connections. Others use timed durations, such as the average
statement execution time. It is also possible to check if
specific configuration elements are present or correct.

In a replication configuration,
the way in which the different
source,
replica, and dual-purpose
source/replica servers are
connected. In MySQL Enterprise Monitor, the configurations are classified in the
Replication view as one of
TREE, RING, or
MIXED.

A data structure often used to represent relationships between
MySQL servers. In the UI,
servers are displayed in the Server
Tree sidebar. In a
replication configuration,
setting up some machines as dual-purpose
master/slave servers produces a
nesting relationship that is represented in the Server Tree.

Predicting when a problem may occur. For example, predicting
that a disk will run out of disk space 30 days in the future.

U

UI

The UI is a web-based interface to the MySQL Enterprise
Service Manager. The back end
is a Java application powered
by the Tomcat server.

UUID

A unique identifier used to distinguish each MySQL
instance, host machine, and
agent. Because there is so much
flexibility in spreading components across multiple systems or
running multiple instances and agents on the same system, the
combination of these different UUIDs identifies where
information came from and the source of any issues. Always
generate a new UUID for any one of these components, rather than
copying or reusing an existing UUID value.

In MySQL 5.5, or earlier, the UUID for the server is stored in
the table mysql.inventory. When a component
such as the Agent or a Connector plugin connects to that MySQL
server, the applicable MySQL user must have privileges to read
this table.